Color
One factor that determines the value of a diamond is its color. With the exception of fancy-colored diamonds, the most valuable diamonds are those with the least color. Although many people think of gem quality diamonds as colorless, completely colorless diamonds are very rare. The diamond color scale ranges from D (colorless) to Z (light yellow or brown). A diamond’s color is determined by a manual process of comparing the diamond to a master set. Each letter grade represents a range of color and is a measurement of how noticeable a color is. When diamonds are formed with traces of other minerals, rare and beautiful colors can result. These “fancy” colors range from blue and brilliant yellow to red, brown, pale green, pink, and violet. Because of their rarity, colored diamonds are highly desirable and typically more valuable.